The present invention relates to a light-emitting device and its manufacturing method and in particular to a light-emitting device that uses a face of a housing part for housing a light-emitting element as a reflector and its manufacturing method.
FIG. 1 is a cross-sectional view of a related art light-emitting device. θ1 shown in FIG. 1 represents the inclination angle of the side face 109A of a housing part 109 with respect to the bottom face 109B of the housing part 109 (hereinafter referred to as the “inclination angle θ1”).
Referring to FIG. 1, the related art light-emitting device 100 includes a substrate 101, a light-emitting element 102, a phosphor-containing resin 103, and a sealing resin 104.
The substrate 101 includes a substrate main body 106 and a wiring pattern 107. The substrate main body 106 includes a housing part 109 and a plurality of through holes 111. The housing part 109 is intended to house the light-emitting element 102. The housing part 109 has a shape that is tapered upward from the bottom 109B of the housing part 109.
The side face 109A of the housing part 109 is an inclined surface forming an inclination angle θ1 with respect to the bottom face 109B of the housing part 109. The side face 109A of the housing part 109 is arranged to surround the light-emitting element 102. The side face 109A of the housing part 109 functions as a reflector to reflect light emitted from the light-emitting element 102. A material for the substrate main body 106 may be ceramic or a resin. Note that a resin has a problem that it is deteriorated by ultraviolet rays contained in the light emitted from the light-emitting element 102 and thus ceramic is preferable as a material for the substrate main body 106. In case ceramic is used as a material for the substrate main body 106, the housing part 109 is formed by countersinking (scraping) a ceramic substrate.
The wiring pattern 107 is arranged to fill the through holes 111 and reach the lower face 106A of the substrate main body 106 via the through holes 111. The light-emitting element 102 is flip-chip connected to the wiring pattern 107 via a bump 112.
The phosphor-containing resin 103 is arranged to cover the light-emitting element 102. The sealing resin 104 is arranged on the housing part 109 so as to seal the light-emitting element 102 covered with the phosphor-containing resin 103. (For example, refer to Patent Reference 1.)
[Patent Reference 1] JP-A-2005-311314
However, the related art light-emitting device 100 forms a housing part 109 by countersinking (scraping) a ceramic substrate, so that it is impossible to obtain a sufficient flatness of the side face 109A of the housing part 109 and it is thus difficult to efficiently reflect the light emitted by the light-emitting element 102 with the side face 109A of the housing part 109. This results in a problem that the lighting efficiency of the light-emitting device 100 is reduced.
The related art light-emitting device 100 has a housing part 109 formed on a substrate 101. For example, to change the inclination angle θ1 of the side face 109A of the housing part 109, the entire substrate 101 must be replaced with another substrate, which adds to the costs of the light-emitting device 100.